It is known mounting onto the bicycle frame, at the front derailleur, a special device configured to prevent the lateral displacement of the chain beyond the toothed crown having the smallest diameter of the crankset when gearshifting is carried out from a crown with a larger diameter to a crown with a smaller diameter.
Examples of such devices are described in US 2010/0172164, US 2011/0230287 and US 2013/0095969.
US 2013/0095969 describes a chain stop device configured to be mounted, in particular, on a bottle holder associated with the bicycle frame. Such a device comprises an element on which a rectilinear portion for attaching to the bottle holder and a curved portion for stopping the chain are defined.
US 2011/0230287 and US 2013/0095969, on the other hand, describe chain stop devices configured to be mounted on the same mounting element on which the front derailleur is mounted.
The Applicant has focussed its attention on the known solutions wherein the chain stop device is mounted on the same mounting element on which the front derailleur is mounted, like for example the solutions described in US 2011/0230287 and US 2013/0095969.
The Applicant has observed that, in order to obtain precise gearshifting while cycling and to allow the chain stop device to effectively carry out its function, both the front derailleur and the chain stop device must be positioned with precision with respect to the crankset.
The Applicant has observed that, in known solutions like for example those described in US 2011/0230287 and US 2013/0095969, the chain stop device is fixed to the mounting element on which the front derailleur is mounted through the same screw that locks the front derailleur onto the aforementioned mounting element. Therefore, whenever an intervention is made on the chain stop device to adjust its position with respect to the crankset, inevitably there is a risk of altering or compromising the correct positioning of the front derailleur with respect to the crankset and vice-versa.
The technical problem at the basis of the present invention is therefore that of being capable of adjusting the position of the chain stop device with respect to the crankset without in any way influencing the correct positioning of the front derailleur with respect to the crankset.